Apparatus for draw forging

ABSTRACT

A draw forging apparatus and method are provided in which six swinging jaws are arranged equi-angularly at 60* to one another around the run-through axis of a work piece to be draw forged, each of which jaws depends from eccentric drives. The jaws are reciprocable in the feed direction by an additional drive. The drives are so interconnected that each three of the jaws offset by 120* relative to one another carry out simultaneous movements in the same direction and operate in antiphase with respect to the other three jaws.

United States Patent [1 1 Kocks et a1.

451 Apia 2 4 ,1973

[ 1 APPARATUS FOR DRAW FORGING [76] Inventors: Friedrich Kocks; Ablert Quainbusch; Bernhard Terdenge, all of 0/0 Friedrich Kocks, Freiligrathstrasse, 4 Dusseldorf, Germany [22] Filed: Feb. 12, 1971 [21] App1. N0.: 114,966

[30] Foreign Application Priority Data Feb. 21, 1970 Germany ..P 20 08 081.3

[52] US. Cl ..72/406 [51] Int. Cl. ..B21j 13/02 [58] Field of Search ..72/406, 402, 450, 72/76, 394, 399

[56] References Cited UNITED STATES PATENTS 3,114,276 12/1963 Uebing ..72/406 3,374,654 3/1968 Uebing ..72/406 3,485,081 12/1969 ....72/406 3,575,029 4/1971 Weber.... ...72/406 3,626,746 12/ 1 971 Pietryka .72/402 Primary Examiner-Charles W. Lanham Assistant ExaminerGene P. Crosby Att0rney-Bue11, Blenko & Ziesenheim [57] ABSTRACT A draw forging apparatus and method are provided in which six swinging jaws are arranged equi-angularly at 60 to one another around the run-through axis of a work piece to be draw forged, each of which jaws depends from eccentric drives. The jaws are reciprocable in the feed direction by an additional drive. The drives are so interconnected that each three of the jaws offset by 120 relative to one another carry out simultaneous movements in the same direction and operate in antiphase with respect to the other three aws.

14 Claims, 2 Drawing Figures APPARATUS FOR DRAW FORGING This invention relates to apparatus for draw forging and particularly to an apparatus for draw forging having swinging jaws which are arranged around the runthrough axis of the block, ingot, billet or bloom to be draw forged. Each jaw depends from two drivable crank devices or eccentric devices by way of swinging jaw links, and the jaws being reciprocable in the feed direction by means of an additional link.

Draw forging apparatus and draw forging practices are not new. In a known and frequently used draw forging apparatus there are four swinging jaws, which are offset by 90 relative to one another about the runthrough axis. The jaws located opposite to one another cooperate in pairs and operate counterwise to the other pair ofjaws. Thus, while one pair ofjaws acts upon the block to be reduced, the other pair of jaws is in the raised position, and vice versa. Considerable reductions in the cross-sectional area can be obtained by means of such draw forging apparatus although these reductions in the cross-sectional area are limited as a result of the considerable broadening occurring during the action of the swingingjaws on the material.

The present invention seeks to provide a draw forging apparatus wherein it is possible to obtain substantially greater reductions in the cross-sectional area than in the case of the known apparatus.

In accordance with a preferred embodiment of the invention, there are provided six swinging jaws, which are offset by 60 relative to one another, and of which three respective jaws, offset by 120 relative to one another, carry out movements in the same direction and work counterwise to the other three jaws.

By the simultaneous operation upon the workpiece by three of the swinging jaws, offset relative to one another by 120, considerable reductions in the crosssectional area can be obtained with good elongation and relatively little spread.

As in four-jaw draw forging apparatus the drive mechanisms for the swingingjaws can be arranged radially behind the swinging jaws in a common plane and in a star-like fashion around the workpiece run-through axis. One or a plurality of drivable torque transmission devices are provided for driving the swinging jaw drive mechanisms, which transmission devices extend at least partially about the arrangement of the drive mechanisms and are connected to the swinging jaw drive mechanisms.

The torque transmission devices may be in the form of two articulate shafts each of which interconnects three adjacent swingingjaw drive mechanisms. The two articulate shafts may be connected to a common drive.

The two articulate shafts may be interconnected by a bevel-gear drive which is arranged in a free space between two swinging jaw drive mechanisms which are not directly interconnected by an articulate shaft, and one of the gear wheels of the bevel-gear drive, or a further bevel gear or spur wheel mounted on the same shaft can mesh with a drive pinion.

Advantageously, a shaft portion forming part of each articulate shaft can be journalled in each of the housings of the swinging jaw drive mechanisms on the end remote from the respective swinging jaw, and the ends of the shaft portions journalled in the center housing of the three drive mechanism housings can be each connected by way of four Cardan joints to the respective ends of the shaft portions journalled in the adjacent drive mechanism housings. In order to increase the stability of the articulate shafts, a short shaft portion which is journalled in a bearing fixed relative to said housings, may be provided between the two center Cardan joints of the four Cardan joints connected one after the other.

In order to prevent distortion of the angular velocities by the Cardan joints, the angles of inclination of all the halves of the Cardan joints are made equal to one another.

For the purpose of transmitting the torque from the drive shafts to eccentric drives of the swinging jaw drive mechanisms, a gear wheel which meshes with a gear wheel of the respective swinging jaw drive mechanism may be provided on each of the shaft portions which are journalled in the drive mechanism housings and which form part of the articulate shafts.

In order to facilitate servicing of the apparatus constructed in accordance with the invention, and to facilitate exchanging of the individual swinging jaws or their drive mechanisms, the latter may be secured to a common rotating frame by means of which the relevant swinging jaw or drive mechanism can be brought into a favorable assembly position. Advantageously, the axis of rotation of the frame corresponds to the run-through axis of the workpiece.

In the foregoing general outline of our invention, we have set out certain objects, purposes and advantages of the invention. Other objects, purposes and advantages of our invention will be apparent from a consideration of the following description and the accompanying drawings in which:

FIG. 1 is a view of draw forging apparatus, constructed in accordance with the invention, seen in the direction of the run-through axis of the workpiece; and

FIG. 2 is a section taken on line Il-II in FIG. 1.

Referring to the drawings, draw forging apparatus constructed in accordance with the invention, includes six swinging jaws 2a, 2b, 2c, 4a,.4b and 40 which are offset by 60 relative to one another. The swinging jaws are arranged around the run-through axis 6 of the workpiece 8 to be reduced and each jaw depends by way of two links 10 and 12 from two eccentrics l4 and 16 which supply the required deformation energy to the respective swinging jaw. To obtain the feed movement of the jaws, there is provided an additional link 20 which is drivable by way of an eccentric 18 and which is pivoted to one of the links (to the link 10 on the delivery side in the present case) on an arm 22 which is extended beyond the eccentric 14 for driving the link 10. Three respective jaws offset relative to one another carry out movements in the same direction and operate out of phase or counterwise with respect to the other three jaws. When the apparatus is in the position illustrated in the drawing, the three swinging jaws 2a, 2b and 2c are acting upon the workpiece and reducing the cross-sectional area thereof and are at the same time effecting the feed movement, while the other three jaws 4a, 4b and 4c are in the raised position and are moving back in the opposite direction to the feed direction.

Six swinging jaw drive mechanisms 24a to 24f are arranged radially behind the swinging jaws in a common plane and in star-like fashion around the run-through axis 6 of the workpiece, and are connected to a common drive (not illustrated in the drawing) by way of two articulate shafts 26 and 28 which interconnect three respective swinging jaw drives located adjacent one another.

As shown in the drawings, the three drive mechanisms 24a, 24b and 240 located at the top are interconnected by way of the articulate shaft 26, while the three drive mechanisms 24d, 24c and 24f located at the bottom are interconnected by way of the articulate shaft 28. Each of the two articulate shafts 26 and 28 includes a respective shaft portion 30a, 30b, 30:: or 30d, 30e, 30f journalled in the housing of the respective swinging jaw drive mechanism at the end of the housing remote from the respective swinging jaw. The ends of the shaft portions 301) and 30e journalled in the center housing of the three swinging jaw drive mechanism housings are connected by four respective Cardan joints 32, 34, 36, 38 to the ends of the respective shaft portions 30a, 30c and 30d, 30f journalled in the adjacent drive mechanism housings. For the purpose of stabilizing the jointed shafts, a short shaft portion 40 is provided between the two center Cardan joints 34, 36 of the four Cardan joints connected one after the other in each articulate shaft, each short shaft portion 40 being journalled in a bearing which is fixed relatively to the housings and which is secured to one of the adjacent housings by a bracket 44. The'angles of inclination of all the halves of the Cardan joints are equal to one another, so that the angular velocities are not distorted.

The joints of each articulate shaft 26 and 28 do not have to transmit more than the torque required for the deformation work of a single swinging jaw, since the swinging jaws 2c and 4b are fed directly by way of the bevel-gear drives and the respective shaft portions 300 and 30d connected thereto, while only one of the swinging jaws 2a and 40 or 2b and 4a is in a working position, while the others are in a position in which they are raised from the workpiece.

The drive for the swinging jaw gears 24a to 24f is taken from the respective shaft portion 30a to 30f which forms part of the articulate shaft and is journalled in the respective housing and on which is arranged a respective spur wheel 31. The spur wheel 31 meshes with a spur wheel 33 which drives the eccentric 18 for the additional link 20. The spur wheel 33 meshes with an intermediate wheel 35 which, by way of spur wheels 37 and 39 meshing therewith, drives the respective eccentrics l4 and 16 of the swinging jaw links and 12.

Referring to FIG. 1, the left hand ends of the two articulate shafts 26 and 28 are interconnected by a bevelgear drive 46 formed by two intermeshing bevel wheels 48 and 50 which are mounted on the adjoining ends of the shaft portions 300 and 30d of the drive shafts. A further bevel wheel 52, which meshes with a bevel pinion 56 mounted on a drive shaft 54, is mounted on the end of the shaft portion 30d projecting from the relevant housing, between the drive mechanism 24d and the bevel gear 50. The two respective pairs of bevel gears 48, 50 and 52,56 are mounted in a separate, horizontally movable housing 58 which can be moved to the left out of the stand after the couplings 60 and 62 shown in FIG. 1 have been disconnected.

The housings of all six drive mechanisms are secured to a common frame 64 which is mounted so as to be rotatable about the run-through axis 6 of the workpiece in journal bearings 66 and 68 rigidly connected to the base. In order to be able to rotate the frame, the couplings 60 and 62 have to be disconnected and the housing 58 has to be removed laterally from the stand together with the two bevel-gear drives. By turning the frame 64, the individual swinging jaws may be brought into an easily accessible position in which they may be exchanged, adjusted or serviced.

By way of example, if the drive mechanism 24blocated at the top in FIG. 1 is to be removed together with its housing, tie bars 70 by which the relevant drive mechanism housing is secured to the frame 64 have to be released, and the articulate shaft has to be disconnected at suitable places. Advantageously, a flanged coupling 72, which interconnects the two respective Cardan joints 36 and 38, is released on each side of the relevant housing.

While we have illustrated and described certain preferred embodiments of out invention in the foregoing specification, it will be obvious that this invention may be otherwise embodied.

We claim:

1. Draw forging apparatus comprising six swinging jaws arranged equi-angularly at 60 to one another around a run-through axis of a workpiece to be draw forged, each of which jaws depends from eccentric drives, said jaws being reciprocable in the feed direction by an additional drive, the drives being so interconnected that each three of the jaws offset by relative to one another carry out simultaneous movements in the same direction to engage substantially the entire periphery of the workpiece and operate in antiphase with respect to the other three jaws.

2. Apparatus as claimed in claim 1 in which the drive mechanisms for the swinging jaws are arranged radially outwardly of the swinging jaws in a common plane and in star-like fashion around the run-through axis of the workpiece and in which at least one drivable torque transmission device for driving the swinging jaw drive mechanisms extends at least partially around the arrangement of the drive mechanisms and is connected thereto.

3. Apparatus as claimed in claim 2 in which there are two torque transmission devices each of which comprises an articulate shaft which interconnects respective three adjacent swinging jaw drive mechanisms.

4. Apparatus as claimed in claim 3 in which the two articulate shafts are connected to a common drive.

5. Apparatus as claimed in claim 4 in which the two articulate shafts are interconnected by a bevel-gear drive which is arranged in the free space between two adjacent swinging jaw drive mechanisms not themselves directly interconnected by an articulate shaft and in which one of the gears of the bevel-gear drive carries a drive gear which meshes with a drive pinion.

6. Apparatus as claimed in claim 3 in which each articulate shaft includes portions journalled in a housing of a respective swinging jaw drive at the end of the housing remote from the respective swinging jaw, and in which each end of the shaft portions journalled in the center housing of each three housings are each connected by way of two Cardan joints to the adjoining end of the shaft portion journalled in an adjacent housing.

7. Apparatus as claimed in claim 6 in which each articulate shaft has short portions between the two Cardan joints, each of said short shaft portions being journalled in a bearing fixed relative to housings.

8. Apparatus as claimed in claim 6 in which the angles of inclination of all like parts of the Cardan joints are equal to one another.

9. Apparatus as claimed in claim 6 in which a gear wheel is provided on each of the shaft portions which are journalled in said housing and which meshes with a gear wheel of the respective swinging jaw drive mechanism.

10. Apparatus as claimed in claim 1 in which the swinging jaw drive mechanisms have housings which are secured to a common rotatable frame.

11. Apparatus as claimed in claim 10, in which the axis of rotation of the frame coincides with the runthrough axis of the workpiece.

12. Apparatus as claimed in claim 1 in which each jaw depends from two crank or eccentric drives by two links.

13. Apparatus as claimed in claim 12 in which said additional drive operates on its respective jaw via an additional link pivoted to one of said two links.

14. A method of draw forging comprising the steps of:

a. passing a workpiece on a pass line between six jaws spaced equi-angularly around the pass line,

b. simultaneously contacting said workpiece with one set of three alternate jaws around substantially all of the periphery of the workpiece, and

c. withdrawing said one set of three alternate jaws and simultaneously contacting said workpiece with the other set of three alternate jaws around substantially all of the periphery of the workpiece. 

1. Draw forging apparatus comprising six swinging jaws arranged equi-angularly at 60* to one another around a run-through axis of a workpiece to be draw forged, each of which jaws depends from eccentric drives, said jaws being reciprocable in the feed direction by an additional drive, the drives being so interconnected that each three of the jaws offset by 120* relative to one another carry out simultaneous movements in the same direction to engage substantially the entire periphery of the workpiece and operate in antiphase with respect to the other three jaws.
 2. Apparatus as claimed in claim 1 in which the drive mechanisms for the swinging jaws are arranged radially outwardly of the swinging jaws in a common plane and in star-like fashion around the run-through axis of the workpiece and in which at least one drivable torque transmission device for driving the swinging jaw drive mechanisms extends at least partially around the arrangement of the drive mechanisms and is connected thereto.
 3. Apparatus as claimed in claim 2 in which there are two torque transmission devices each of which comprises an articulate shaft which interconnects respective three adjacent swinging jaw drive mechanisms.
 4. Apparatus as claimed in claim 3 in which the two articulate shafts are connected to a common drive.
 5. Apparatus as claimed in claim 4 in which the two articulate shafts are interconnected by a bevel-gear drive which is arranged in the free space between two adjacent swinging jaw drive mechanisms not themselves directly interconnected by an articulate shaft and in which one of the gears of the bevel-gear drive carries a drive gear which meshes with a drive pinion.
 6. Apparatus as claimed in claim 3 in which each articulate shaft includes portions journalled in a housing of a respective swinging jaw drive at the end of the housing remote from the respective swinging jaw, and in which each end of the shaft portions journalled in the center housing of each three housings are each connected by way of two Cardan joints to the adjoining end of the shaft portion journalled in an adjacent housing.
 7. Apparatus as claimed in claim 6 in which each articulate shaft has short portions between the two Cardan joints, each of said short shaft portions being journalled in a bearing fixed relative to housings.
 8. Apparatus as claimed in claim 6 in which the angles of inclination of all like parts of the Cardan joints are equal to one another.
 9. Apparatus as claimed in claim 6 in which a gear wheel is provided on each of the shaft portions which are journalled in said housing and which meshes with a gear wheel of the respective swinging jaw drive mechanism.
 10. Apparatus as claimed in claim 1 in which the swinging jaw drive mechanisms have housings which are secured to a common rotatable frame.
 11. Apparatus as claimed in claim 10, in which the axis of rotation of the frame coincides with the run-through axis of the workpiece.
 12. Apparatus as claimed in claim 1 in which each jaw depends from two crank or eccentric drives by two links.
 13. Apparatus As claimed in claim 12 in which said additional drive operates on its respective jaw via an additional link pivoted to one of said two links.
 14. A method of draw forging comprising the steps of: a. passing a workpiece on a pass line between six jaws spaced equi-angularly around the pass line, b. simultaneously contacting said workpiece with one set of three alternate jaws around substantially all of the periphery of the workpiece, and c. withdrawing said one set of three alternate jaws and simultaneously contacting said workpiece with the other set of three alternate jaws around substantially all of the periphery of the workpiece. 